Evaluate the pharmacokinetic properties of indinavir in the CSF of patients with HIV disease. This prospective study will utilize a highly intensive continous CSFsampling technique and will characterize the CSF pharmacokinetics of indinavir in HIB-infected patients receiving indinavir and lamivudine, plus zidovudine or stavudine, and to compare the CST and plasma concentration-time profile of indinavir, including CSF/plasma ratios of pharmacokinetic parameters.